While weddings often don't run according to plan, Jessica finds that her nephew Grady's marriage takes the cake for dilemmas. Dealing with the new in-laws presents enough problems, but the roof blows out when the Mayberrys' maid, Harriet, turns up dead in the petunias. In order to get the wedding back on track, Jessica has to sort out which of the guests or temporary employees had reason to kill.
This episode includes examples of the following tropes:
- Amicable Exes: Donna and Wilfred, the boyfriend her parents wanted her to marry, broke up some time before, but they still have a very friendly relationship. When Wilfred arrives, he gives Donna a bear hug (making her giggle) and says he wouldn't have missed seeing her get married for a Grateful Dead concert.
- Bluff the Imposter: Jessica gets evidence "Cousin Clara" isn't a family member when she describes the fair-haired Donna as a brunette and sees that she fails to catch it. Clara confesses she's a gatecrasher.
- Casanova Wannabe: Uncle Ben flirts with (and often gropes) everything in a skirt. Harriet threatens him with a knife and Jessica shoots him a glare and shuts the door in his face.
- Food Slap: When Uncle Ben implicitly suggests he and she running off to get married in Vegas, Ziggy's wife asks him how he'd like a cup of hot coffee in his lap.
- He Knows Too Much: Harriet ended up dead because she could identify Ziggy's new wife as a woman, Mrs. Parker, who had disappeared after coming under suspicion of murdering her previous husband.
- In the Back: Harriet is killed by being stabbed in the back. With a meat thermometer, of all things.
- Just Here for the Free Snacks: Jessica finds out that "Cousin Clara" is a gatecrasher who likes to attend weddings for the fun and for the good food she can eat (and stuff in her purse for later).
- Not Now, Kiddo: The children who find the body run to tell their father, who's occupied talking business with Mr. Mayberry. He tries to brush them off but eventually gets pestered into finding out the problem.
- Parent-Preferred Suitor: Jessica's nephew/adoptive son Grady gets married to his fiancée Donna Mayberry. Donna's upper class parents don't approve of her choice, voicing their wishes that their daughter would marry her old boyfriend Wilfred even on her wedding day. They change their tune when Wilfred, whom they remember as proper and straitlaced, arrives for the wedding and turns out to have become a traveling rock-and-roll groupie.
- Pun-Based Title: The title references the old poem which describes what a bride needs to carry on her wedding day: "Something old, something new, something borrowed, something blue."
- Red Herring: "Cousin" Clara isn't related to anyone at the family, but she's also not the murderer, or even remotely troublesome. She's just a gate crasher.
- Rewatch Bonus: Harriet refers to Ziggy's date as "Mrs. Parker" when she first sees her, something which proves crucial later on as it means Harriet knew the woman under a different name.
- Shotgun Wedding: One of the relatives at the wedding says that she heard Donna is pregnant, presumably explaining why she's getting married to a young man who hasn't got her connections or money.
- Speak Now or Forever Hold Your Peace: Given how much has already gotten in the way of the wedding, several people tense the moment the preacher gets to this part of the ceremony. However, nobody and nothing interrupts.
- Tempting Fate: Jessica, trying to reassure her stressed nephew, tells him that the worst has already happened. Then Harriet's body turns up in the flowerbed and things get much more stressful.
- Worst Wedding Ever: Predictably, Jessica can't even attend her nephew's wedding without coming across a murder, which quickly supersedes all the more prosaic problems that occur beforehand. Jessica rolls her eyes skyward in relief when the pastor finally tells Grady to kiss the bride.
